code: def setUpClass(cls):
      init_default_scope("mmdet")
      tracker_cfg = dict(
          type="MaskTrackRCNNTracker",
          match_weights=dict(det_score=1.0, iou=2.0, det_label=10.0),
          num_frames_retain=20,
      )
      cls.tracker = MODELS.build(tracker_cfg)
      cls.num_objs = 5
  
file_path: mmdetection/tests/test_models/test_trackers/test_masktrack_rcnn_tracker.py
imports: from unittest import TestCase
  import torch
  from mmengine.registry import init_default_scope
  from parameterized import parameterized
  from mmdet.registry import MODELS
  from mmdet.testing import demo_track_inputs, get_detector_cfg, random_boxes
label_desc: Use image node_id 1 for calling the TestMaskTrackRCNNTracker obj's underlying member method code with example usage: obj.setUpClass(cls) without return types